Sleep Disorders

Sleep Apnea

Sleep apnea, sometimes spelled "apnoea" - one of the most
potentially dangerous sleep disorders - is when the patient stops breathing
during regularly sleep. The term apnea literarily means "without
breath". The period of stoppage is usually short (a few seconds)
before breathing resumes. The seriousness of apnea varies considerably
and depends on how long the sleep stoppages are how many happen. Experts
estimate apnea
affects 1 in 15 people or 18 million Americans. Men are more susceptible
to sleep apnea than women. "All-cause" mortality risk increases significantly with apnea. The worse the apnea, the higher the risk of death from a number of factors.

There are three types of sleep apnea: central sleep apnea , obstructive
sleep apnea and complex sleep apnea. Obstructive sleep apnea is the
most common type.

Obstructive sleep apnea (OSA) is an obstruction
of the airway passage that results in a decreased level of oxygen
in the blood. The obstructions cause a choking or gasping along with
loud snoring during sleep. These choking and gasping episodes briefly
arouses the person and can happen as frequently as 20 to 30 times
per hour. For this reason a person with sleep apnea cannot get a good
night’s rest. Apnea can also cause a headache in the morning, a dry
mouth, tiredness during the day, and reduced libido. Central sleep
apnea has similar characteristics to OSA, but lacks the loud snoring
aspect. In both cases the person awakes suddenly during the night
choking or gasping for air.

The reasons why some people are afflicted with sleep apnea are not
well understood. Researchers believe there are genetic components.
Identification of a single gene is not likely and the current theory
points to multiple genes as a plausible cause. One study demonstrated
a correlation between obstructive sleep apnea and developing hypertension.
The researchers followed individuals with OSA and those that had more
than 15 obstructive wake-ups per hour were more likely to develop
hypertension within the next 4 years. They also found that those who
did not receive treatment had an increase risk for cardiovascular
morbidity and mortality. A more recent study suggests that the relationship
between apnea and hypertension is because of obesity. Obesity is a
major factor in both conditions, while apnea might sometimes be the
cause of the hypertension, this condition is more likely caused by
high body weight and other factors. High blood pressure and apnea
are "co-morbidities". People with moderate-to-severe OSA
can have extensive brain
changes, possibly because of the repeated hypoxia. A study presented at the International Stroke Conference in 2012 found that apnea patients have a higher risk of strokes and brain lesions. Many apnea patients also have abnormal swallowing while asleep, although this problem does not typically reach a magnitude where it is considered clinically significant.

Sleep deprivation and apnea can put stress on the body and raise
blood pressure and cause the release of cytokines by the immune system,
putting further strain on the cardiovascular system. Sleep-disordered
breathing may cause abnormal lipid metabolism, and SDB and deprivation
may be tied to metabolic syndrome, which affects tens of millions
of Americans. Apnea increases the risk of hypertension, regardless
of the person’s age, sex, or level of obesity. An article by Greek doctors even playfully called apnea and resistant
hypertension “sparring partners”.

Obstructive sleep apnea is correlated with metabolic syndrome, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1978322/ although some of the components of metabolic syndrome – diabetes and high cholesterol – did not show correlation with apnea at levels high enough to be considered statistically significant.

Central sleep apnea is much less common, but potentially
very dangerous. Central sleep apnea is caused by the failure of brain
to transmit signals to the body to breathe, in contrast to obstructive
sleep apnea is due to a physical block that obstructs air flow to
the lungs.

Cheyne-Stokes respiration is when there is a crescendo - decrescendo
pattern of respiration. It occurs in people with congestive heart
failure or stroke. Drug or substance abuse, especially over
consumption of a respiratory depressant drug may cause central sleep
apnea. Alcohol, opiates, benzodiazepines, barbiturates, and some kinds
of tranquilizers are respiratory depressants. Breathing at high altitude
also causes sleep apnea. In some cases the causes are not known, these
cases are “idiopathic central sleep apnea”.

People with certain heart and neuromuscular disorders are also in
danger of central sleep apnea.

During an incident of central sleep apnea if the intervals in breathing
are too spread apart, the oxygen level in the bloodstream falls below
the normal level and the amount of carbon dioxide increases. Thess
abnormal blood levels can cause negative effects on a range of organs;
if oxygen level remains low for a long time it can lead to brain damage
or even death. The severity of the apnea and the physical fitness
of the patient are factors in how well the body can withstand the
apnea. Lack of oxygen can cause seizures even in people who have no
history of epilepsy and in people with diagnosed epilepsy, but who
have it under control, it can cause seizures again and for people
with heart diseases it can cause arrhythmias, angina or heart attack.

Sleep-related laryngospasm

A related symptom some apnea sufferers get is sleep-related laryngospasm. The sleeper wakes up suddenly and feeling alarmed that he or she is suffocating. Any attempts to speak come out as a wheeze. People who have these spasms often have gastro-oesophageal reflux, too, leading doctors to hypothesize a connection where the stomach acids reach the larynx and irritate the tissue. It is also connected to surgery on the larynx.

Birth Defects

Cleft lips and palates are the most common birth defects and may
affect sleep breathing. Surgical repair of the airway can help,
although sometimes people have apnea and other problems even after
surgery.

Treatment of Obstructive Sleep Apnea

The most common treatment for obstructive sleep apnea is termed
continuous positive airway
pressure or CPAP. The positive pressure is generated by a machine
that sits next to the bed and has a mask connected to it that the
person wears while sleeping. It forces pressure into the nose and
mouth so the airway does not collapse and the person sleeps without
choking or gasping awakenings. While CPAP machines increase the quality
of sleep, excessive sleepiness does not always go away, in these people
modafinil or armodafinil may be used as a treatment. These drugs help
to maintain wakefulness during the day.

CPAP is the most common treatment, but surgery called uvulopalatopharyngoplasty is also an option. Your physician may recommend weight loss, avoidance
of alcohol/sedatives, or sleeping in a position other than the back.
Removing the tonsils or adenoids also can relieve apnea, especially in children. During the diagnosis process there is a series of tests and the test
scores as a measure of severity will determine which course of treatment
should be taken. (A sample Berlin Questionairre can be seen here.) For those having trouble with CPAP upon exhaling
against the positive pressure there is a modified machine called bilevel
positive airway pressure or BPAP and this decreases the pressure during
exhalation and increases the pressure during inhalation. There have
been several pharmacologic treatments tested, but none of them have
yielded results similar to treatment with positive airway pressure.
If a person is unwilling or unable to use positive airway pressure
machines, surgery is an option. The federal government publishes a
guideline on "Diagnosis
and treatment of obstructive apnea in adults."

Surgery is not always effective in eliminating the apnea, although it may be beneficial if it reduces the severity of symptoms. Peripheral arterial tonometry - often in a wrist unit the patient can wear to bed - can be used to keep tabs on how the patient is doing following the surgery.

Drugs are not used to directly treat apnea, but there is interest among researchers in developing pharmacological treatment that targets the anatomy and mechanism of the breathing system. A combination of domperidone (normally used to suppress vomiting and nausea) and the antihistimine pseudoephedrine has been tried in a study at a Department of Veterans Affairs hospital. There was also interest in replacing the pseudoephedrine with phenylephrine, a decongestant that is often used in place of pseudoephedrine. This idea was that these drugs would help open passageways for airflow.

Weight loss is often the best way to definitively reduce the effects of apnea, and one advantage is that the patient
gets doesn't have to use the CPAP machine or a mouthguard, both of
which tend to be abandoned by patients as being too bothersome.

In 2007 the professional journal Sleep featured a debate about whether mild apnea should be treated. The opposing view (that it should not be treated) rested on low patient compliance with CPAP and the fact that observations of people with mild to moderate apnea who do use the CPAP regularly do not show significant improvements in daytime sleepiness (objective or subjective) and blood pressure. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2564770/

The author of this article thinks mild apnea should be addressed by trying to get the sleeper to cut alcohol consumption, lose weight, and generally practice good sleep hygiene.

Acetazolamide for Apnea

The drug acetazolamide is used to treat mountain sickness (which can include altitude insomnia) and research suggests it might help out people with apnea. The drug, sold under the brand name Diamox, helps increase oxygen levels in the bloodstream. When people ascend to alpine levels, they sometimes have trouble getting enough oxygen. Apnea produces some of the same effects, and Swiss scientists found acetazolamide may help, although this is not yet an accepted treatment.

Treatment of Central Sleep Apnea

Numerous techniques can be used to treat central sleep apnea. . Reducing
the consumption of respiratory suppressant drugs also helps. If the
cause is due to a heart or a neuromuscular condition, treatment of
the disorder can cure the apnea. Supplemental Oxygen and devices like
CPAP machines, Bi-level positive airway pressure, Adaptive servo-ventilation
help in supply of oxygen to the brain by aiding the respiratory process.

Sleeping in the lateral position on the back has been found to be
helpful in cases of central sleep apnea. Medications like acerazlamide
and theophyllinr lower the pH level of the blood and helps in respiration
are used by some doctors to treat sleep apnea patients. People who
display symptoms of central sleep apnea should consult a physician
at the earliest since delays in treating this disease may lead to
life threatening conditions.

Diagnosis and Warnings

Sleep apnea is highly undiagnosed. According to
a National Health Institute estimate, only 25 percent of Americans
with apnea symptoms sought medical attention over a 4-year period.
Indeed, one of the goals of the government's Health People initiative
is to raise this percentage.

A polysomnography
is done to detect sleep apnea. In the test the heart, brain and lung
activities are tested during sleep to check any abnormality. Oximetry might also be done to check the blood oxygen level during sleep. In
some cases MRI might also be done.

If a person is experiencing excessive daytime tiredness along with
frequent night arousals accompanied by a choking or gasping for air
feeling, they should talk to their clinician about sleep apnea. Excessive
tiredness can lead to many side effects such as endangering your life
or others when driving. Severe mood changes, mental dysfunction, and
libido reduction are also associated with sleep apnea.

The Apnea-Hyponea Index was created to quantify the severity of apnea. There are difference indices; the simplest counts the number of breathing stoppages per hour, with under 5 considered normal (no apnea). Mild apnea is 5 to 15 incidences per hour, moderate 15-30, and severe greater than 30. There is some controversey because different ways of measuring apnea lead to different results; this is an area where diagnostic standards could be improved.

State laws may require that doctors who know about excessivly sleepy
people (clincal name for condition: excessive daytime sleepiness)
report them to the motor vehicle bureau. The American Thoracic Society
(a professional medical group) does not recommend physicians interfere
with driving privileges unless the patient has been in a crash or
some other event indicates particularly high risk. The society recommends
doctors report patients only if they have been in an accident, has
apnea that cannot be treated, or refuses treatment within two months
of diagnosis.

Neurogenic Tachypnea

Neurogenic tachypnea is a disorder of breathing -
is when people breath fast and shallow.
Neurogenic tachypnea is sometimes the beginnings of neurodegenerative
disease. Which is why it is important that your doctor check you out.

Seasonality

Recent epidemiological work has shown that apnea symptoms are worse during the winter. Part of the the increase in disordered breathing may be due to allergies and seasonal weight gain (many people get heavier in the winter.) Weather conditions such as high atmospheric pressure (more common in winter), high humidity (more common in summer) and carbon monoxide (more common in urban areas) make apnea worse. Colds and general irritation of the respiratory system are worse in the winter, which can exacerbate apnea symptoms.

The University of Michigan made this video that gives a good overview of apnea:

In the 1950's a medical writer coined the term Pickwickian syndrome to describe sleep-disordered breathing. The character Joe did not appear to actually have apnea as we currently understand it. However, you sometimes see Pickwickian syndrome used to describe sleep disordered breathing.

Medication?

A 2007 article in the Journal of the American Academy of Pain Medicine
talks about the connection between opioid medication and sleep apnea.
Researchers looked at patients taking opioids for chronic pain and
found they had a higher incidence of apnea. This is not surprising
as opioids relax the muscles and that includes the throat area. However,
these patients did not have the crescendo-decrescendo breath size
pattern characteristic of people with central sleep apnea.

There is some
evidence that the antidepressant medication mirtazapine (Remeron)
helps relieve apnea. This is the most effective drug for apnea found
so far, but the evidence is based only on a small trial. Mirtazapine
is not used widely in apnea treatment.

Apnea also leads to memory problems. For a long time doctors thought
the decline in short term memory ability was due to sleep deprivation.
New findings indicate the apnea actually causes shrinkage in areas
of the brain important to memory. Use of CPAP machines and regular
exercise seems to help.